Copper requirements of animals and pastures in New Zealand pastoral agriculture - a review

Abstract

More copper (Cu) is required for the growth of cattle and deer than sheep and pasture. National and regional farm surveys showed that mean pasture Cu concentrations were generally within or above the required range for pasture growth and lambs but below that for cattle and deer. Pasture concentrations of molybdenum (Mo) of up to 7 mg/kg for lambs and 10 mg/kg for deer had no effect on liveweight gain provided that pasture Cu concentrations were 7 to 8 mg/kg or greater. From twenty-one sites, there was a significant response to Cu in animal liveweight gain and wool weight only from lambs injected monthly with Cu and deer grazing pasture top dressed with copper sulphur, both on pasture with high Mo concentrations. Daily drenching of animals with copper sulphate or chelated Cu and the use of Cu capsules or copper oxide (CuO) wire particles was more effective at increasing liver Cu concentration than Cu injections or topdressing with copper sulphate. There was a significant pasture yield response measured on Recent and podzolised soils that had pasture Cu concentrations in the deficient range. There is a need for more research on the response in liveweight gain of cattle and deer from different Cu treatments at varying pasture Mo concentrations.